239928981 has 4 divisors (see below), whose sum is σ = 319905312. Its totient is φ = 159952652.

The previous prime is 239928971. The next prime is 239929003. The reversal of 239928981 is 189829932.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 239928981 - 2⁶ = 239928917 is a prime.

It is a super-2 number, since 2×239928981² = 115131831847396722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (239928971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39988161 + ... + 39988166.

It is an arithmetic number, because the mean of its divisors is an integer number (79976328).

Almost surely, 2^239928981 is an apocalyptic number.

It is an amenable number.

239928981 is a deficient number, since it is larger than the sum of its proper divisors (79976331).

239928981 is an equidigital number, since it uses as much as digits as its factorization.

239928981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79976330.

The product of its digits is 559872, while the sum is 51.

The square root of 239928981 is about 15489.6410868683. The cubic root of 239928981 is about 621.3851972142.

The spelling of 239928981 in words is "two hundred thirty-nine million, nine hundred twenty-eight thousand, nine hundred eighty-one".